Generally, a typical control system for a reciprocating object includes a microprocessor, a limit switch, a drive circuit, a keyboard and a display. A position signal exerted by the limit switch is inputted to the microprocessor as the measurement of the travel of the object. The microprocessor provides the drive circuit with a control signal to define the next movement of the object depending on a command from the keyboard and a position feedback signal. The display is used for displaying the working status and the control mode of the control system. In a control system for a small-sized reciprocating object, usually a button and an indicating lamp are used instead of the keyboard and the display in order to reduce cost and save space. However, when the movement modes of the object are complex, for example, in the case of a plurality of different selectable travel modes, it is necessary to provide a plurality of buttons to define the control modes, and to provide a plurality of indicating lamps to indicate the working status. This requires the microprocessor to have a number of on-off signal input/output ports, resulting in greater complexity for the microprocessor and its control circuit.